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  /*! \file
   * \brief
   * Declares gmx::IAnalysisDataModule and related convenience classes.
   *
   * \author Teemu Murtola <teemu.murtola@gmail.com>
   * \inlibraryapi
   * \ingroup module_analysisdata
   */
  #ifndef GMX_ANALYSISDATA_DATAMODULE_H
  #define GMX_ANALYSISDATA_DATAMODULE_H
  
  namespace gmx
  {
  
  class AbstractAnalysisData;
  class AnalysisDataFrameHeader;
  class AnalysisDataParallelOptions;
  class AnalysisDataPointSetRef;
  
  /*! \brief
   * Interface for a module that gets notified whenever data is added.
   *
   * The interface provides one method (flags()) that describes features of
   * data objects the module supports.  Only most common features are included
   * in the flags; custom checks can be implemented in the dataStarted() and/or
   * parallelDataStarted() methods (see below).
   * All other methods in the interface are callbacks that are called by the
   * data object to which the module is attached to describe the data.
   * See \ref module_analysisdata for an overview of the notifications the
   * modules receive, and \ref page_analysisdata for overview of the terminology.
   *
   * Concrete modules typically do not directly derive from this interface, but
   * from either AnalysisDataModuleSerial or AnalysisDataModuleParallel.
   * Both these classes implement one of dataStarted()/parallelDataStarted() by
   * forwarding the calls to the other method of this pair.  This allows the
   * module to only implement the initialization once, without needing to worry
   * how to correctly handle both cases.
   *
   * Currently, if the module throws an exception, it requires the analysis tool
   * to terminate, since AbstractAnalysisData will be left in a state where it
   * is not possible to continue processing.  See a related todo item in
   * AbstractAnalysisData.
   *
   * \inlibraryapi
   * \ingroup module_analysisdata
   */
  class IAnalysisDataModule
  {
  public:
      /*! \brief
       * Possible flags for flags().
       */
      enum Flag
      {
          //! The module can process multipoint data.
          efAllowMultipoint = 1 << 0,
          //! The module does not make sense for non-multipoint data.
          efOnlyMultipoint = 1 << 1,
          //! The module can process data with more than one column.
          efAllowMulticolumn = 1 << 2,
          //! The module can process data with missing points.
          efAllowMissing = 1 << 3,
          //! The module can process data with multiple data sets.
          efAllowMultipleDataSets = 1 << 4
      };
  
      virtual ~IAnalysisDataModule() {}
  
      /*! \brief
       * Returns properties supported by the module.
       *
       * The return value of this method should not change after the module
       * has been added to a data (this responsibility can, and in most cases
       * must, be delegated to the user of the module).
       *
       * The purpose of this method is to remove the need for common checks
       * for data compatibility in the classes that implement the interface.
       * Instead, AbstractAnalysisData performs these checks based on the
       * flags provided.
       *
       * Does not throw.
       */
      virtual int flags() const = 0;
  
      /*! \brief
       * Called (once) when the data has been set up properly.
       *
       * \param[in] data  Data object to which the module is added.
       * \throws    APIError if the provided data is not compatible.
       * \throws    unspecified  Can throw any exception required by the
       *      implementing class to report errors.
       *
       * When the data is ready, either this method or parallelDataStarted()
       * is called, depending on the nature of the input data.  If this
       * method is called, the input data will always present the frames in
       * sequential order.
       *
       * The data to which the module is attached is passed as an argument
       * to provide access to properties of the data for initialization
       * and/or validation.  The module can also call
       * AbstractAnalysisData::requestStorage() if needed.
       *
       * This is the only place where the module gets access to the data;
       * if properties of the data are required later, the module should
       * store them internally.  It is guaranteed that the data properties
       * (column count, whether it's multipoint) do not change once this
       * method has been called.
       *
       * Notice that \p data will be a proxy object if the module is added as
       * a column module, not the data object for which
       * AbstractAnalysisData::addColumnModule() was called.
       */
      virtual void dataStarted(AbstractAnalysisData* data) = 0;
      /*! \brief
       * Called (once) for parallel data when the data has been set up.
       *
       * \param[in] data     Data object to which the module is added.
       * \param[in] options  Parallelization properties of the input data.
       * \returns   true if the module can process the input in
       *      non-sequential order.
       * \throws    APIError if the provided data is not compatible.
       * \throws    unspecified  Can throw any exception required by the
       *      implementing class to report errors.
       *
       * This method is called instead of dataStarted() if the input data has
       * the capability to present data in non-sequential order.
       * If the method returns true, then the module accepts this and frame
       * notification methods may be called in that non-sequential order.
       * If the method returns false, then the frame notification methods are
       * called in sequential order, as if dataStarted() had been called.
       *
       * See dataStarted() for general information on initializing the data.
       * That applies to this method as well, with the exception that calling
       * AbstractAnalysisData::requestStorage() is currently not very well
       * supported (or rather, accessing the requested storage doesn't work).
       */
      virtual bool parallelDataStarted(AbstractAnalysisData*              data,
                                       const AnalysisDataParallelOptions& options) = 0;
      /*! \brief
       * Called at the start of each data frame.
       *
       * \param[in] frame  Header information for the frame that is starting.
       * \throws    unspecified  Can throw any exception required by the
       *      implementing class to report errors.
       */
      virtual void frameStarted(const AnalysisDataFrameHeader& frame) = 0;
      /*! \brief
       * Called one or more times during each data frame.
       *
       * \param[in] points  Set of points added (also provides access to
       *      frame-level data).
       * \throws    APIError if the provided data is not compatible.
       * \throws    unspecified  Can throw any exception required by the
       *      implementing class to report errors.
       *
       * Can be called once or multiple times for a frame.  For all data
       * objects currently implemented in the library (and all objects that
       * will use AnalysisDataStorage for internal implementation), it is
       * called exactly once for each frame if the data is not multipoint,
       * but currently this restriction is not enforced.
       */
      virtual void pointsAdded(const AnalysisDataPointSetRef& points) = 0;
      /*! \brief
       * Called when a data frame is finished.
       *
       * \param[in] header  Header information for the frame that is ending.
       * \throws    unspecified  Can throw any exception required by the
       *      implementing class to report errors.
       */
      virtual void frameFinished(const AnalysisDataFrameHeader& header) = 0;
      /*! \brief
       * Called in sequential order for each frame after they are finished.
       *
       * \param[in] frameIndex   Index of the next finished frame.
       * \throws    unspecified  Can throw any exception required by the
       *      implementing class to report errors.
       *
       * This method is called after frameFinished(), but with an additional
       * constraint that it is always called in serial and with an increasing
       * \p frameIndex.  Parallel data modules need this to serialize their
       * data for downstream serial modules; AnalysisDataModuleSerial provides
       * an empty implementation, as there frameFinished() can be used for
       * the same purpose.
       */
      virtual void frameFinishedSerial(int frameIndex) = 0;
      /*! \brief
       * Called (once) when no more data is available.
       *
       * \throws    unspecified  Can throw any exception required by the
       *      implementing class to report errors.
       */
      virtual void dataFinished() = 0;
  };
  
  /*! \brief
   * Convenience base class for serial analysis data modules.
   *
   * Implements the parallelDataStarted() method such that initialization is
   * always forwarded to dataStarted(), and the module always behaves as serial
   * (parallelDataStarted() returns false).
   *
   * \inlibraryapi
   * \ingroup module_analysisdata
   */
  class AnalysisDataModuleSerial : public IAnalysisDataModule
  {
  public:
      ~AnalysisDataModuleSerial() override {}
  
      int flags() const override = 0;
  
      void dataStarted(AbstractAnalysisData* data) override              = 0;
      void frameStarted(const AnalysisDataFrameHeader& frame) override   = 0;
      void pointsAdded(const AnalysisDataPointSetRef& points) override   = 0;
      void frameFinished(const AnalysisDataFrameHeader& header) override = 0;
      void dataFinished() override                                       = 0;
  
  private:
      bool parallelDataStarted(AbstractAnalysisData* data, const AnalysisDataParallelOptions& options) override;
      void frameFinishedSerial(int /*frameIndex*/) override {}
  };
  
  /*! \brief
   * Convenience base class for parallel analysis data modules.
   *
   * Implements the dataStarted() method such that initialization is always done
   * in parallelDataStarted().  dataStarted() calls are forwarded to
   * parallelDataStarted() using a dummy serial AnalysisDataParallelOptions.
   *
   * \inlibraryapi
   * \ingroup module_analysisdata
   */
  class AnalysisDataModuleParallel : public IAnalysisDataModule
  {
  public:
      ~AnalysisDataModuleParallel() override {}
  
      int flags() const override = 0;
  
      bool parallelDataStarted(AbstractAnalysisData*              data,
                               const AnalysisDataParallelOptions& options) override = 0;
      void frameStarted(const AnalysisDataFrameHeader& frame) override              = 0;
      void pointsAdded(const AnalysisDataPointSetRef& points) override              = 0;
      void frameFinished(const AnalysisDataFrameHeader& header) override            = 0;
      void frameFinishedSerial(int index) override                                  = 0;
      void dataFinished() override                                                  = 0;
  
  private:
      void dataStarted(AbstractAnalysisData* data) override;
  };
  
  } // namespace gmx
  
  #endif
  